For those that stumble across this thread in the future, DO NOT buy a Dymo LabelWriter 450 and expect it to integrate with QuickBooks. They did for years, but if you are using the version from 2018 forward, forget it. Here is their actual response. 

Dear Don,

Thank you for contacting us.

I am sorry to hear that you are experiencing issues with our product.

I have contacted my Technical Team for assistance and I regret to inform you that the QuickBooks Pro versions after 2018 are no longer supported. There are currently no plans on updating the software. 

I deeply apologize for the inconvenience.

If I can be of further assistance, please reply to this email directly.

Thank you for using DYMO,

Mikolaj

DYMO Consumer Service

Reach us on:

1-877-724-8324, Monday to Friday: 9:00 AM - 5:00 PM

________________________________________

I purchased a brand new LabelWriter 450 in February 2020 to go along with my new Quickbooks Pro 2020 upgrade I was doing. I quickly found your priinter no longer integrates with Quickbooks Pro 2020, to allow me to capture a customer address directly from an open invoice, as I have done for years. I called your support and got a person who told me "Oh that has not worked since 2018, and I don't think we are going to fix it". Not the answer I was looking for. I need a fix for the problem. I cannot be a big deal. It worked fine for years until I upgraded. Awaiting your response.